To evaluate the efficacy of two different doses of intravenous dexamethasone on the duration of subarachnoid block in patients undergoing infraumbilical surgery : A randomized control double blind study

Introduction

The subarachnoidblock is the most commonly used block for infraumbilical surgeries. This helpsin avoiding risks of general anaesthesia like difficulty in airway management,gastric aspiration and nausea and vomiting [1]. Local anaesthetic, Bupivacaineis appropriate for procedures of 90-180 minutes duration.

Many additives havebeen used so far to improve the onset and quality of subarachnoid block. Thesemedications improves quality and duration of sensory block. Various additiveslike opioids, clonidine, ketamine , dexmedetomedine and manymore have been used .

Dexamethasone relievespain by reducing inflammation, blocking transmission of nociceptive c-fibersand by suppressing ectopic neural discharge [2]. In addition it also increases the duration ofpost operatives analgesia, when given iv with the local anaesthestics in subarachnoidblock , few  studies showssignificant  prolongation of subarachnoidblock while using dexamethasone as additive [3,4].

Few studies publishedin the literature had shown the effect of addition of intravenous dexamethasoneon subarachnoid block duration, post-operative analgesia and reduced analgesicrequirement [3, 5].

Purpose of thisstudy- To evaluate theeffect of two different doses of IV dexamethasone with intrathecal bupivacaineon prolongation of duration and quality of analgesia of subarachnoid block inpatients undergoing infraumbilical surgery.

Why we choose this study:

Some studies have shownthat intravenous dexamethasone with intrathecal bupivacaine in LSCS (lowersection cesarean section), it significantly prolongs the duration of sensoryblock and post op analgesia [3].

We didn’t find any studyusing two different doses of IV dexamethasone in subarachnoid block.

As for spinal itrequires preservative free dexamethasone which will be difficult to get inIndia. So we decided to use dexamethasone by intravenous route.

 Reference

1)     Brown DL. Miller’sanesthesia. Elsevier Churchill Livingstone. 2005;43:1653-83.

 2) Golwala MP,Swadia VN, Aditi A, Dhimar, Sridbar NV. Pain relief by dexamethasone as anadjuvantto local anesthetics in supraclavicular brachial plexus block. J AnesthClin Pharmacol. 2009;25:285–8.

 3) Shalu PS, Ghodki PS. To Study the Efficacy ofIntravenous Dexamethasone in Prolonging the Duration of Spinal Anesthesia inElective Cesarean Section. Anesth Essays Res. 2017 Apr-Jun;11(2):321-325. doi:10.4103/0259-1162.194537. PMID: 28663614; PMCID: PMC5490098.

4. Bani-Hashem N, Hassan-Nasab B, Pour EA, MalehPA, Nabavi A, Jabbari A. Addition of intrathecal Dexamethasone to Bupivacainefor spinal anesthesia in orthopedic surgery. Saudi J Anaesth. 2011Oct;5(4):382-6. doi: 10.4103/1658-354X.87267. PMID: 22144925; PMCID:PMC3227307.

 5) Kadur,S.N. & Ahmed, F. & Purohit, A. & Khandelwal, M. & Mistry,Tuhin. (2015). The effect of intravenous dexamethasone on postoperative pain,nausea and vomiting after intrathecal pethidine and bupivacaine in lower limborthopedic surgery. 19. 254-259.